168517872137 has 2 divisors, whose sum is σ = 168517872138. Its totient is φ = 168517872136.

The previous prime is 168517871989. The next prime is 168517872143. The reversal of 168517872137 is 731278715861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 168478232521 + 39639616 = 410461^2 + 6296^2 .

It is a cyclic number.

It is not a de Polignac number, because 168517872137 - 2¹⁸ = 168517609993 is a prime.

It is not a weakly prime, because it can be changed into another prime (168517872197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84258936068 + 84258936069.

It is an arithmetic number, because the mean of its divisors is an integer number (84258936069).

Almost surely, 2^168517872137 is an apocalyptic number.

It is an amenable number.

168517872137 is a deficient number, since it is larger than the sum of its proper divisors (1).

168517872137 is an equidigital number, since it uses as much as digits as its factorization.

168517872137 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3951360, while the sum is 56.

The spelling of 168517872137 in words is "one hundred sixty-eight billion, five hundred seventeen million, eight hundred seventy-two thousand, one hundred thirty-seven".